Fluid clutch actuators



June 14, 1960 c. P. WARMAN, JR 2,940,572

FLUID CLUTCH ACTUATORS Filed June 28, 1 954 INVENTOR.

CHARLES WARM/4M, JP-

ATT).

United States Patent 2,940,512 FLUID CLUTCH ACTUATORS Charles P. Warman,Jr., P.0. Box 1150, Wichita Falls, Tex.

Filed June 28, 1954, Ser. No. 439,731

Claims. 01. 192-88) This invention relates to certain new and usefulimprovements in fluid clutch actuators for clutches and brakes and thelike. A study of previous practice in the art reveals the use of twomain types of fluid actuators for these uses, viz., the'enclosed tubetype and the diaphragm type, each having its peculiar advantages anddisadvantages. The said enclosed tube type actuators having relativefreedom from fluid leakage and relative ease of replacement by unskilledpersons; and the disadvantages of high original cost and the capabilityof only limited expansive action before elficiency losses are noted. Thediaphragm actuators are relatively lower in acquisition cost and arecapable of designs which allow expansion to compensate for extremes inclutch facing or brake lining wear while retaining high operatingefficiencies, but are subject to fluid leaks unless installed withconsiderable care by expert mechanics.

It is an object of this invention to provide a fluid propelled actuatorfor said uses which incorporates the best features of diaphragm typeactuators and enclosed tube actuators, While eliminating the,inherent-disadvantages of such structures, and providing certain novelactions and features not formerly available in either of theaforementioned types. a V

Afurther'object of this invention is to provide a fluid distensible'actuator capable of being 'constructed'so as to exert the actuatingforce in any of the manners employed in clutches and brakes discussedherein, whether axial thrust, expansive radial pressure, or constrictiveradial pressure.

..These and other objects of my invention will become readily apparentto 'those Sklllfid'lfl the art from the following description ofpossible specific forms of the device, reference being made for thatpurpose to the accompanying drawings in which:

Fig. I is a vertical cross section of a disc type clutch or brakeassembly utilizing one form of my actuator.

Fig. II is a cross sectional view of one form of my actuator in use in aclutch or brake assembly, illustrating its adaptability in mechanisms ofthe type in which an' expansive radial pressure is required.

Fig. III is a partial cross sectional view of my actuator removed fromany associated part and showing one possible modification ofconstruction details.

Referring to the several drawings, wherein like references indicatesimilar parts throughout the several views, 1 is a driving or drivenshaft, according to the application of the assembly, and which isvariously rotatively connected or disconnected with housing 2, suchconnection or disconnection of said parts being the function of theclutch or brake assembly as shown, and being efiected by inflation ordeflation of actuator 3 by the required movement of a suitable fluidthrough passageways 4 into annular cavity 5 of the actuator through theannular opening extending around its inner face. In the structure asillustrated in Fig. I such inflation causes the actuator to 'distend byflattening of the semi-circular sides 3a and magnitude of which variesdirectly with the magnitude of the fiuid pressure. Said thrust isimpressed through a clutch actuating surface 9 to heat insulator element6 causing the conventional disc type clutch or brake mechanism to beengaged.

One of the elements of the clutch has an annular recess 16 havingopposed sides 14in Fig. I, which sides may also be undercut as at 14a inFig. II. The resilient actuator 3 comprises a modified toroidal memberhaving mutually opposed parallel actuator Walls 9 and 18, joined by apair offlexing end walls 3a of essentially semicircular cross-section.The actuator wall 18 is discon-. tinuous to form an annular opening ofwidth approximating the spacingbetween the centers of the semicircularflexing walls 3a, and the edges of the opening each ter minate in-aflange 15 standing normal to the plane of. the actuator wall 18, theflanges 15 having heel surfaces 13. In Fig. 11 the heel surface islabeled 13a and makes an acute angle with the plane of the discontinuousactuutor wall 18a so as to complement the shape of the undercut edge 14aof the recess.

In the structure as illustrated in Fig. II, inflation causes:

the actuator to distend radially outwardly from the element 8 to whichit is attached at its inner actuating wall 18a, said actuator carryingat its outer actuating wall 9a a clutch or brake facing 7 to forcecontact with housing 2, causing housing 2 and element 8 to engage in acommon rotational engagement.

Alternatively, it is clearly evident that by causing thev actuator to beconstructed so that face 9a lies in the inner; diameter of the actuatorbody, and the flanges 15 in-,- cluding sealing lips 10 and beads 11changed in accord ing relation on the outer diameter, my actuator would;

then be properly adapted to generate restrictive radial thrust toachieve the desired result in properly associ ated mechanisms of thetypes here under consideration.

In a preferred form of actuator construction, thatpart of the actuatorwhich forms the seal between the actuator and the mounting element isconstructed as illustrated in Fig. III. Bead members 11, in the flange15a, are-made, of wire, either single or stranded, or other similarmaterial particularly adapted to resist tensile stresses such as will beimposed by forces of rotation generated during phases of operation ofthe assembly. Single or multiple plies of reinforcing 12 may becompo'sed'of fabric, or similar material. in its various forms, and isimbedded in and bonded to the rubber or rubber-like material which;composes the remainder of the actuator. It is significant that, in myactuator, no metal insert is employed which becomes external to, and/orpasses through the rubber wall, such as is required in construction ofthe closed tube type actuator in order to provide air-tight connectionmeans.

My actuator in any of its various forms is put into operation by firstcausing the part to be fabricated according to conventional bonding andmolding techniques ordinarily employed in the manufacture of similaritems. Final structural shape at the inner surface of the actuator inthe vicinity of the flanges, including sealing lips 10 and/or heels 13,or 13a as a possible variation, is formed during the molding operation.Annular recesses 16 including sides 14 or undercut lock type sides areprovided in the clutch or brake housing to receive heels 13 or 13arespectively. The combination of lock type sides 14a and acute angledheel surfaces 13a is indicated advisable when, as illustrated in Fig.II, the construction f Patented June14, 1960 bingan a a -25? In hactu'ato'r'as set forthingplaim 1, reenforoing plete by-simply pressinginto place by involving I 'no multiple screw; or other fastenings, suchas relied upon to both hold in place and prevent fluid leakage arounddiaphragmtype actuators. By, forming the related parts 7 "r' a 21 itsassociatedjpartifafcei the initial mech anicalr seal and thepressureseal, can b'e l0 pro ision jofflipfltl he"modifica tion as a Vil f i i nat airtime odd 5 th I are if d'scop oftlle "arr clairn is.

ap edatftiiatd walls 1 about iniifually 'spaced center's cross-sectionstaken 25 in planes including said axis; Jone oftlie opposed acts 1 g V iscontinuous "to: rorm an' 'annular aid axis and or widthappijoirialladjacent the r ening-ge natin f; a sage wailat anjangletnogreatefthan'QOf' t V Inan actuator "as j's'et forth: in 1, said andhaving a pairof nautually' parallelopposed V actuator walls joined by apair of mutually opposedend walls, the latter comprising 'convex flexingwalls of the between therespeetiye'centers ofsaid-semicircular flexingwalls and each edge of the discontinuous Wall adjacent the openingterminating" in a *fian'ge standiii'gf substantially r "normal to theplaneof said discontinuous wall and extending y ft om't ot r 9mat ;;yll;1 he: flanges each haying-a heel surface meeting the adjacent outersurface of said discontinudiis wall=at ani anglenovgreater than 90 andcomplementary withthe sides offs'aid recess. 7; In a combination a's'set forth in clairn 6; said'recess sides being undercut and said anglebeing an acute 8: In a comb nationas;set iforth'i claim 6, theitwoj 7flanges'each dravifng a' resilient sealing lip e rtending' to ward the"other flange and overlying atleastj part' of the surface of saidrecess'betwersaid opposed sides-: 5

19: Infaconibinationas set forth in claim sgsaid' recess sides'heing"nnderc'ufand' saidfang'le being an acuterangle.

10:17In a combinationas settiorthtin-"claim 6; reenforo' 'ing' beadsiimbe'dded-t'andbbhded'in at least one 'of said flanges to increase thetensile" strength the'reof-iopposing distortion ofthe?flangesduring'rotation?- tR eferengesiited in tlgefile o th i lifi'tmf UNITED STATES BATENTYS .2o o.9 ".D 1140131 18 w1,159,1 9 957512,120,182

